Minimize Outlook to the System Tray
If your Windows taskbar is getting crowded, but you prefer to keep Microsoft Outlook open all the time, you can add an Outlook icon to the system tray.
Use the Registry to Minimize Outlook
If you prefer to make the change using the Windows Registry, first create a system restore point and then follow these steps:
What to Do If Outlook Still Shows in the Task Bar
If you can still see the Outlook icon in the Windows taskbar, it may be pinned to it. To remove a closed or minimized Outlook from the taskbar:
Restore Outlook After It Has Been Minimized to the System Tray
To open Outlook again after it has been hidden on the system tray and disappeared from the taskbar, double-click the Outlook system tray icon. Or, right-click the Outlook system tray icon and select Open Outlook.
Make Sure the Outlook System Tray Icon Is Visible
To unhide and make visible the Outlook icon in the main system tray: